2002 25hp johnson Idle problem

[DJD775]

I recently ran into a problem with my outboard. The motor was running fine for the first half hour of the trip then I decided to slow down and switch gas tanks beacuse one was running low. About a minute after switching the the tank the motor began to run roughly at 1/4 throttle and would stall if idled. I made sure the vent was open on the tank. I decided to switch back to the other tank and the problem continued. I headed back to port and when motor was opened up it seemed to have about 1/2-3/4 of it's normal power. My thought is that it might be a clogged jet, does anyone have any idea's what the problem could be?

 

[G DANE]

Re: 2002 25hp johnson Idle problem

Are you sure there wasnt a couple of drops of water in the other tank ? In the bottum of your carbureator float bowl, there is a drain screw. Try to remove it and pres your primer bulb a couple of times. Fuel and whatever lies loose in the float bowl will run out. Just a couple of drops of water will block the high speed jet some. Next step would be cleaning all filters on fuel inlet on motor, just follow fuel hose, inside hood. Third step if first didnt help, would be disassemble and soaking, cleaning carb throughly. Try some of above and post back, most likely water.

 

[fireman57]

Re: 2002 25hp johnson Idle problem

It could be that you had a bad coincidence happen too. Check for spark on plug wires. Sounds like you could have dropped a cylinder. I check these first because it is easy to do and elimnates firing right away as the problem. I have had many a powerpack go bad in an instant. The sudden loss of power describes it perfectly. You and G Dane could be exactly right could be a carb prob and clogged jet. I like trying to eliminate the easy problems before tearing down.

 

[DJD775]

Re: 2002 25hp johnson Idle problem

Thanks for your posts. I checked both cylinders and they have spark. I drained the fuel out of the bowl and it looked fine. Tried to start the engine won't start(first time trying to start cold). Checked the fuel filter looks fine. Removed carb and cleaned even though it looked clean already. Can't start and raw fuel is coming out of the prop. I think it is about time for a call to the dealer.

 

[fireman57]

Re: 2002 25hp johnson Idle problem

Is the float set properly and the needle valve seated?

 

[BugEyes]

Re: 2002 25hp johnson Idle problem

I don't know if the engines are still constructed the same way but on my 1980 25 hp Evinrude I had the same sympthoms. Turned out to be a stopper in the trottle linkage that had slipped on the rod on the left side of the flywheel, the rod that goes from the top of the arm to the carb. The effect of that was that the the mechanic ignition advance (rotating stator plate) went way out of synch to the carb and thus resulted in way too much ignition advance on low RPM.

 

[DJD775]

Re: 2002 25hp johnson Idle problem

I finally got the motor repaired and it ended up being a broken reed valve. According to the mechanic it said this problem is very rare.